Sherlock Holmes

Hi, I'm currently playing Kerbal Space Program version 1.3.1. I downloaded North Kerbin Weaponary, Module Manager, BdArmory, and Kerbal engineer. (I also checked if it is the right version for 1.3.1) However, when I make an attempt to launch or drop some bombs and missiles, it says "Weapon Manager Not Found." even though I have on attached on the plane. I tried to fix it by myself for more than a week, and it still doesn't work. Can anyone help me?